Thiazol sulfonic acid.



UNITED- STATES PATENT @FFTCE.

ALFRED THAUSS, OF ELBERFELD, GERMANY, ASSIGNQR TO FAR-BEN- FABRIKEN OF ELBERFELD (30., OF NEW YORK, N. Y., A CORPORA- TION OF NEV YORK.

THIAZOL SULFONIC ACID.

Specification of Letters Patent.

1 a.tented Aug. 1, 1905.

Application filed April 27, 1905. Serial No. 257,671.

. ds the condensation products (benzylidene compounds) obtainable from aromatic aldehydes-such as benzaldehyde, meta-nitrobenzaldehyde, or the likeand 2-5-amidonaphthol-7-sulfonic acid.

The new thiazol sulfonic acids produced in the above-defined manner are, in the shape of their alkaline salts, from whitish to grayish powders soluble in water. They combine with diazo-benzene, forming thus red dyestuffs directly dyeing cotton.

In carrying out my new process practically I can proceed as follows, the parts being by weight: 15.1 parts of meta-nitrobenzaldehyde are added to a solution of twentysiX parts of 25-amidonaphthol7-sulfonate of sodium in two hundred parts of hot water. The aldehyde enters quickly into solution, with the production of the benzylidene com pound. After the addition of a concentrated solution of thirty parts of sulfur and seventyfive parts of crystallized sodium sulfid in water it is heated to boiling for twenty-four hours at a reflux condenser. With disengagement of hydrogen sulfid the thiazol nucleus is formed, the nitro group being reduced at the same time. The solution thus obtained is then filtered in order to remove therefrom the precipitated sulfur and acidulated by the addition of sulfuric acid in order to precipitate the new compound. The acid thus separated in the shape of faint-yellow crystals having the formula:

(meta-amidobenzenylthio 2- 5 amidonaphthol-7-sulfonic acid,-) is soluble with difficulty in water. It is converted into its sodium salt, which is easily soluble in hot Water, by means of sodium carbonate and then freed from admixed sulfur by redissolving it from hot water. It can either combine with diazo-benzene, forming thus a red dyestufi' directly dyeing cotton, or can be diazotized itself and then combined with dyestuif components. The free acid is a yellowish-brown powder which is but scarcely soluble in water. The process for obtaining the abovecited thiaZol-sulfonic acids proceeds in an analogous manner on using other aromatic aldehydes.

Having now described my invention and in what manner the same is to be performed, what I claim is 1. The herein-described new thiazol-sulfonic acids having the above-given formula,

ing a yellowish-brown powder, but scarcely name in the presence of two subscribing \vitsoluble in Water; capable of comblnmg With nesses. dlazobenzene thus formlng a red dyestufl,

directly dyeing cotton, and of being diazotized ALFRED THAUSS' itself and then be combined With dyestufi Witnesses: components, substantially as described. OTTO KNIG,

In testimony whereof I have signed my ALEX Goos. 

